1 /* vi: set sw=4 ts=4: */
3 * Mini diff implementation for busybox, adapted from OpenBSD diff.
5 * Copyright (C) 2006 by Robert Sullivan <cogito.ergo.cogito@hotmail.com>
6 * Copyright (c) 2003 Todd C. Miller <Todd.Miller@courtesan.com>
8 * Sponsored in part by the Defense Advanced Research Projects
9 * Agency (DARPA) and Air Force Research Laboratory, Air Force
10 * Materiel Command, USAF, under agreement number F39502-99-1-0512.
12 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
17 #define FSIZE_MAX 32768
22 #define D_HEADER 1 /* Print a header/footer between files */
23 #define D_EMPTY1 2 /* Treat first file as empty (/dev/null) */
24 #define D_EMPTY2 4 /* Treat second file as empty (/dev/null) */
27 * Status values for print_status() and diffreg() return values
29 * D_SAME - files are the same
30 * D_DIFFER - files differ
31 * D_BINARY - binary files differ
32 * D_COMMON - subdirectory common to both dirs
33 * D_ONLY - file only exists in one dir
34 * D_MISMATCH1 - path1 a dir, path2 a file
35 * D_MISMATCH2 - path1 a file, path2 a dir
36 * D_ERROR - error occurred
37 * D_SKIPPED1 - skipped path1 as it is a special file
38 * D_SKIPPED2 - skipped path2 as it is a special file
42 #define D_DIFFER (1<<0)
43 #define D_BINARY (1<<1)
44 #define D_COMMON (1<<2)
46 #define D_MISMATCH1 (1<<4)
47 #define D_MISMATCH2 (1<<5)
48 #define D_ERROR (1<<6)
49 #define D_SKIPPED1 (1<<7)
50 #define D_SKIPPED2 (1<<8)
52 /* Command line options */
53 static unsigned long cmd_flags;
65 #define FLAG_t (1<<10)
66 #define FLAG_T (1<<11)
67 #define FLAG_U (1<<12)
68 #define FLAG_w (1<<13)
71 char *start, *label[2];
72 struct stat stb1, stb2;
88 * The following struct is used to record change information
89 * doing a "context" or "unified" diff. (see routine "change" to
90 * understand the highly mnemonic field names)
93 int a; /* start line in old file */
94 int b; /* end line in old file */
95 int c; /* start line in new file */
96 int d; /* end line in new file */
99 static int *J; /* will be overlaid on class */
100 static int *class; /* will be overlaid on file[0] */
101 static int *klist; /* will be overlaid on file[0] after class */
102 static int *member; /* will be overlaid on file[1] */
105 static int pref, suff; /* length of prefix and suffix */
107 static int anychange;
108 static long *ixnew; /* will be overlaid on file[1] */
109 static long *ixold; /* will be overlaid on klist */
110 static struct cand *clist; /* merely a free storage pot for candidates */
111 static int clistlen; /* the length of clist */
112 static struct line *sfile[2]; /* shortened by pruning common prefix/suffix */
113 static struct context_vec *context_vec_start;
114 static struct context_vec *context_vec_end;
115 static struct context_vec *context_vec_ptr;
117 static void print_only(const char *path, size_t dirlen, const char *entry)
121 printf("Only in %.*s: %s\n", (int) dirlen, path, entry);
124 static void print_status(int val, char *path1, char *path2, char *entry)
126 const char *const _entry = entry ? entry : "";
127 char *_path1 = entry ? concat_path_file(path1, _entry) : path1;
128 char *_path2 = entry ? concat_path_file(path2, _entry) : path2;
132 print_only(path1, strlen(path1), entry);
135 printf("Common subdirectories: %s and %s\n", _path1, _path2);
138 printf("Binary files %s and %s differ\n", _path1, _path2);
141 if (cmd_flags & FLAG_q)
142 printf("Files %s and %s differ\n", _path1, _path2);
145 if (cmd_flags & FLAG_s)
146 printf("Files %s and %s are identical\n", _path1, _path2);
149 printf("File %s is a directory while file %s is a regular file\n",
153 printf("File %s is a regular file while file %s is a directory\n",
157 printf("File %s is not a regular file or directory and was skipped\n",
161 printf("File %s is not a regular file or directory and was skipped\n",
172 * Hash function taken from Robert Sedgewick, Algorithms in C, 3d ed., p 578.
174 static int readhash(FILE * f)
181 if (!(cmd_flags & FLAG_b) && !(cmd_flags & FLAG_w)) {
183 for (i = 0; (t = getc(f)) != '\n'; i++) {
191 for (i = 0; (t = getc(f)) != '\n'; i++) {
201 switch (t = getc(f)) {
210 if (space && !(cmd_flags & FLAG_w)) {
228 * There is a remote possibility that we end up with a zero sum.
229 * Zero is used as an EOF marker, so return 1 instead.
231 return (sum == 0 ? 1 : sum);
237 * Check to see if the given files differ.
238 * Returns 0 if they are the same, 1 if different, and -1 on error.
240 static int files_differ(FILE * f1, FILE * f2, int flags)
242 char buf1[BUFSIZ], buf2[BUFSIZ];
245 if ((flags & (D_EMPTY1 | D_EMPTY2)) || stb1.st_size != stb2.st_size ||
246 (stb1.st_mode & S_IFMT) != (stb2.st_mode & S_IFMT))
249 i = fread(buf1, 1, sizeof(buf1), f1);
250 j = fread(buf2, 1, sizeof(buf2), f2);
253 if (i == 0 && j == 0) {
254 if (ferror(f1) || ferror(f2))
258 if (memcmp(buf1, buf2, i) != 0)
263 static void prepare(int i, FILE * fd, off_t filesize)
271 sz = (filesize <= FSIZE_MAX ? filesize : FSIZE_MAX) / 25;
275 p = xmalloc((sz + 3) * sizeof(struct line));
276 for (j = 0; (h = readhash(fd));) {
279 p = xrealloc(p, (sz + 3) * sizeof(struct line));
287 static void prune(void)
291 for (pref = 0; pref < len[0] && pref < len[1] &&
292 file[0][pref + 1].value == file[1][pref + 1].value; pref++);
293 for (suff = 0; suff < len[0] - pref && suff < len[1] - pref &&
294 file[0][len[0] - suff].value == file[1][len[1] - suff].value;
296 for (j = 0; j < 2; j++) {
297 sfile[j] = file[j] + pref;
298 slen[j] = len[j] - pref - suff;
299 for (i = 0; i <= slen[j]; i++)
300 sfile[j][i].serial = i;
304 static void equiv(struct line *a, int n, struct line *b, int m, int *c)
309 while (i <= n && j <= m) {
310 if (a[i].value < b[j].value)
312 else if (a[i].value == b[j].value)
323 while (b[j + 1].value == b[j].value) {
331 static int isqrt(int n)
343 } while ((x - y) > 1 || (x - y) < -1);
348 static int newcand(int x, int y, int pred)
352 if (clen == clistlen) {
353 clistlen = clistlen * 11 / 10;
354 clist = xrealloc(clist, clistlen * sizeof(struct cand));
364 static int search(int *c, int k, int y)
368 if (clist[c[k]].y < y) /* quick look for typical case */
388 static int stone(int *a, int n, int *b, int *c)
392 unsigned int numtries;
394 #if ENABLE_FEATURE_DIFF_MINIMAL
395 const unsigned int bound =
396 (cmd_flags & FLAG_d) ? UINT_MAX : MAX(256, isqrt(n));
398 const unsigned int bound = MAX(256, isqrt(n));
401 c[0] = newcand(0, 0, 0);
402 for (i = 1; i <= n; i++) {
411 if (y <= clist[oldc].y)
417 if (clist[c[l]].y <= y)
420 c[l] = newcand(i, y, oldc);
425 c[l] = newcand(i, y, oldc);
429 } while ((y = b[++j]) > 0 && numtries < bound);
434 static void unravel(int p)
439 for (i = 0; i <= len[0]; i++)
440 J[i] = i <= pref ? i : i > len[0] - suff ? i + len[1] - len[0] : 0;
441 for (q = clist + p; q->y != 0; q = clist + q->pred)
442 J[q->x + pref] = q->y + pref;
446 static void unsort(struct line *f, int l, int *b)
450 a = xmalloc((l + 1) * sizeof(int));
451 for (i = 1; i <= l; i++)
452 a[f[i].serial] = f[i].value;
453 for (i = 1; i <= l; i++)
458 static int skipline(FILE * f)
462 for (i = 1; (c = getc(f)) != '\n' && c != EOF; i++)
469 * Check does double duty:
470 * 1. ferret out any fortuitous correspondences due
471 * to confounding by hashing (which result in "jackpot")
472 * 2. collect random access indexes to the two files
474 static void check(FILE * f1, FILE * f2)
476 int i, j, jackpot, c, d;
482 ixold[0] = ixnew[0] = 0;
485 for (i = 1; i <= len[0]; i++) {
487 ixold[i] = ctold += skipline(f1);
491 ixnew[j] = ctnew += skipline(f2);
494 if ((cmd_flags & FLAG_b) || (cmd_flags & FLAG_w)
495 || (cmd_flags & FLAG_i)) {
500 * GNU diff ignores a missing newline
501 * in one file if bflag || wflag.
503 if (((cmd_flags & FLAG_b) || (cmd_flags & FLAG_w)) &&
504 ((c == EOF && d == '\n') || (c == '\n' && d == EOF))) {
509 if ((cmd_flags & FLAG_b) && isspace(c) && isspace(d)) {
514 } while (isspace(c = getc(f1)));
519 } while (isspace(d = getc(f2)));
520 } else if (cmd_flags & FLAG_w) {
521 while (isspace(c) && c != '\n') {
525 while (isspace(d) && d != '\n') {
533 if (c != '\n' && c != EOF)
534 ctold += skipline(f1);
535 if (d != '\n' && c != EOF)
536 ctnew += skipline(f2);
539 if (c == '\n' || c == EOF)
546 if ((c = getc(f1)) != (d = getc(f2))) {
548 if (c != '\n' && c != EOF)
549 ctold += skipline(f1);
550 if (d != '\n' && c != EOF)
551 ctnew += skipline(f2);
554 if (c == '\n' || c == EOF)
562 for (; j <= len[1]; j++)
563 ixnew[j] = ctnew += skipline(f2);
566 /* shellsort CACM #201 */
567 static void sort(struct line *a, int n)
569 struct line *ai, *aim, w;
574 for (j = 1; j <= n; j *= 2)
576 for (m /= 2; m != 0; m /= 2) {
578 for (j = 1; j <= k; j++) {
579 for (ai = &a[j]; ai > a; ai -= m) {
582 break; /* wraparound */
583 if (aim->value > ai[0].value ||
584 (aim->value == ai[0].value && aim->serial > ai[0].serial))
586 w.value = ai[0].value;
587 ai[0].value = aim->value;
588 aim->value = w.value;
589 w.serial = ai[0].serial;
590 ai[0].serial = aim->serial;
591 aim->serial = w.serial;
598 static void uni_range(int a, int b)
601 printf("%d,%d", a, b - a + 1);
608 static int fetch(long *f, int a, int b, FILE * lb, int ch)
610 int i, j, c, lastc, col, nc;
614 for (i = a; i <= b; i++) {
615 fseek(lb, f[i - 1], SEEK_SET);
616 nc = f[i] - f[i - 1];
619 if (cmd_flags & FLAG_T)
623 for (j = 0, lastc = '\0'; j < nc; j++, lastc = c) {
624 if ((c = getc(lb)) == EOF) {
625 puts("\n\\ No newline at end of file");
628 if (c == '\t' && (cmd_flags & FLAG_t)) {
641 static int asciifile(FILE * f)
643 #if ENABLE_FEATURE_DIFF_BINARY
644 unsigned char buf[BUFSIZ];
648 if ((cmd_flags & FLAG_a) || f == NULL)
651 #if ENABLE_FEATURE_DIFF_BINARY
653 cnt = fread(buf, 1, sizeof(buf), f);
654 for (i = 0; i < cnt; i++) {
655 if (!isprint(buf[i]) && !isspace(buf[i])) {
663 /* dump accumulated "unified" diff changes */
664 static void dump_unified_vec(FILE * f1, FILE * f2)
666 struct context_vec *cvp = context_vec_start;
667 int lowa, upb, lowc, upd;
671 if (context_vec_start > context_vec_ptr)
675 lowa = MAX(1, cvp->a - context);
676 upb = MIN(len[0], context_vec_ptr->b + context);
677 lowc = MAX(1, cvp->c - context);
678 upd = MIN(len[1], context_vec_ptr->d + context);
680 fputs("@@ -", stdout);
681 uni_range(lowa, upb);
683 uni_range(lowc, upd);
684 fputs(" @@", stdout);
688 * Output changes in "unified" diff format--the old and new lines
689 * are printed together.
691 for (; cvp <= context_vec_ptr; cvp++) {
698 * c: both new and old changes
699 * d: only changes in the old file
700 * a: only changes in the new file
702 if (a <= b && c <= d)
705 ch = (a <= b) ? 'd' : 'a';
706 if (ch == 'c' || ch == 'd') {
707 fetch(ixold, lowa, a - 1, f1, ' ');
708 fetch(ixold, a, b, f1, '-');
711 fetch(ixnew, lowc, c - 1, f2, ' ');
712 if (ch == 'c' || ch == 'a')
713 fetch(ixnew, c, d, f2, '+');
717 fetch(ixnew, d + 1, upd, f2, ' ');
719 context_vec_ptr = context_vec_start - 1;
723 static void print_header(const char *file1, const char *file2)
725 if (label[0] != NULL)
726 printf("%s %s\n", "---", label[0]);
728 printf("%s %s\t%s", "---", file1, ctime(&stb1.st_mtime));
729 if (label[1] != NULL)
730 printf("%s %s\n", "+++", label[1]);
732 printf("%s %s\t%s", "+++", file2, ctime(&stb2.st_mtime));
738 * Indicate that there is a difference between lines a and b of the from file
739 * to get to lines c to d of the to file. If a is greater then b then there
740 * are no lines in the from file involved and this means that there were
741 * lines appended (beginning at b). If c is greater than d then there are
742 * lines missing from the to file.
744 static void change(char *file1, FILE * f1, char *file2, FILE * f2, int a,
747 static size_t max_context = 64;
751 if (cmd_flags & FLAG_q)
755 * Allocate change records as needed.
757 if (context_vec_ptr == context_vec_end - 1) {
758 ptrdiff_t offset = context_vec_ptr - context_vec_start;
761 context_vec_start = xrealloc(context_vec_start,
763 sizeof(struct context_vec));
764 context_vec_end = context_vec_start + max_context;
765 context_vec_ptr = context_vec_start + offset;
767 if (anychange == 0) {
769 * Print the context/unidiff header first time through.
771 print_header(file1, file2);
773 } else if (a > context_vec_ptr->b + (2 * context) + 1 &&
774 c > context_vec_ptr->d + (2 * context) + 1) {
776 * If this change is more than 'context' lines from the
777 * previous change, dump the record and reset it.
779 dump_unified_vec(f1, f2);
782 context_vec_ptr->a = a;
783 context_vec_ptr->b = b;
784 context_vec_ptr->c = c;
785 context_vec_ptr->d = d;
791 static void output(char *file1, FILE * f1, char *file2, FILE * f2)
794 /* Note that j0 and j1 can't be used as they are defined in math.h.
795 * This also allows the rather amusing variable 'j00'... */
796 int m, i0, i1, j00, j01;
802 J[m + 1] = len[1] + 1;
803 for (i0 = 1; i0 <= m; i0 = i1 + 1) {
804 while (i0 <= m && J[i0] == J[i0 - 1] + 1)
808 while (i1 < m && J[i1 + 1] == 0)
812 change(file1, f1, file2, f2, i0, i1, j00, j01);
815 change(file1, f1, file2, f2, 1, 0, 1, len[1]);
817 if (anychange != 0) {
818 dump_unified_vec(f1, f2);
823 * The following code uses an algorithm due to Harold Stone,
824 * which finds a pair of longest identical subsequences in
827 * The major goal is to generate the match vector J.
828 * J[i] is the index of the line in file1 corresponding
829 * to line i file0. J[i] = 0 if there is no
830 * such line in file1.
832 * Lines are hashed so as to work in core. All potential
833 * matches are located by sorting the lines of each file
834 * on the hash (called ``value''). In particular, this
835 * collects the equivalence classes in file1 together.
836 * Subroutine equiv replaces the value of each line in
837 * file0 by the index of the first element of its
838 * matching equivalence in (the reordered) file1.
839 * To save space equiv squeezes file1 into a single
840 * array member in which the equivalence classes
841 * are simply concatenated, except that their first
842 * members are flagged by changing sign.
844 * Next the indices that point into member are unsorted into
845 * array class according to the original order of file0.
847 * The cleverness lies in routine stone. This marches
848 * through the lines of file0, developing a vector klist
849 * of "k-candidates". At step i a k-candidate is a matched
850 * pair of lines x,y (x in file0 y in file1) such that
851 * there is a common subsequence of length k
852 * between the first i lines of file0 and the first y
853 * lines of file1, but there is no such subsequence for
854 * any smaller y. x is the earliest possible mate to y
855 * that occurs in such a subsequence.
857 * Whenever any of the members of the equivalence class of
858 * lines in file1 matable to a line in file0 has serial number
859 * less than the y of some k-candidate, that k-candidate
860 * with the smallest such y is replaced. The new
861 * k-candidate is chained (via pred) to the current
862 * k-1 candidate so that the actual subsequence can
863 * be recovered. When a member has serial number greater
864 * that the y of all k-candidates, the klist is extended.
865 * At the end, the longest subsequence is pulled out
866 * and placed in the array J by unravel
868 * With J in hand, the matches there recorded are
869 * checked against reality to assure that no spurious
870 * matches have crept in due to hashing. If they have,
871 * they are broken, and "jackpot" is recorded--a harmless
872 * matter except that a true match for a spuriously
873 * mated line may now be unnecessarily reported as a change.
875 * Much of the complexity of the program comes simply
876 * from trying to minimize core utilization and
877 * maximize the range of doable problems by dynamically
878 * allocating what is needed and reusing what is not.
879 * The core requirements for problems larger than somewhat
880 * are (in words) 2*length(file0) + length(file1) +
881 * 3*(number of k-candidates installed), typically about
882 * 6n words for files of length n.
885 static int diffreg(char *ofile1, char *ofile2, int flags)
887 char *file1 = ofile1;
888 char *file2 = ofile2;
895 context_vec_ptr = context_vec_start - 1;
897 if (S_ISDIR(stb1.st_mode) != S_ISDIR(stb2.st_mode))
898 return (S_ISDIR(stb1.st_mode) ? D_MISMATCH1 : D_MISMATCH2);
899 if (strcmp(file1, "-") == 0 && strcmp(file2, "-") == 0)
902 if (flags & D_EMPTY1)
903 f1 = xfopen(bb_dev_null, "r");
905 if (strcmp(file1, "-") == 0)
908 f1 = xfopen(file1, "r");
911 if (flags & D_EMPTY2)
912 f2 = xfopen(bb_dev_null, "r");
914 if (strcmp(file2, "-") == 0)
917 f2 = xfopen(file2, "r");
920 if ((i = files_differ(f1, f2, flags)) == 0)
922 else if (i != 1) { /* 1 == ok */
928 if (!asciifile(f1) || !asciifile(f2)) {
934 prepare(0, f1, stb1.st_size);
935 prepare(1, f2, stb2.st_size);
937 sort(sfile[0], slen[0]);
938 sort(sfile[1], slen[1]);
940 member = (int *) file[1];
941 equiv(sfile[0], slen[0], sfile[1], slen[1], member);
942 member = xrealloc(member, (slen[1] + 2) * sizeof(int));
944 class = (int *) file[0];
945 unsort(sfile[0], slen[0], class);
946 class = xrealloc(class, (slen[0] + 2) * sizeof(int));
948 klist = xmalloc((slen[0] + 2) * sizeof(int));
951 clist = xmalloc(clistlen * sizeof(struct cand));
952 i = stone(class, slen[0], member, klist);
956 J = xrealloc(J, (len[0] + 2) * sizeof(int));
961 ixold = xrealloc(ixold, (len[0] + 2) * sizeof(long));
962 ixnew = xrealloc(ixnew, (len[1] + 2) * sizeof(long));
964 output(file1, f1, file2, f2);
983 #if ENABLE_FEATURE_DIFF_DIR
984 static void do_diff(char *dir1, char *path1, char *dir2, char *path2)
987 int flags = D_HEADER;
990 char *fullpath1 = xasprintf("%s/%s", dir1, path1);
991 char *fullpath2 = xasprintf("%s/%s", dir2, path2);
993 if (stat(fullpath1, &stb1) != 0) {
995 memset(&stb1, 0, sizeof(stb1));
996 fullpath1 = xasprintf("%s/%s", dir1, path2);
998 if (stat(fullpath2, &stb2) != 0) {
1000 memset(&stb2, 0, sizeof(stb2));
1001 stb2.st_mode = stb1.st_mode;
1002 fullpath2 = xasprintf("%s/%s", dir2, path1);
1005 if (stb1.st_mode == 0)
1006 stb1.st_mode = stb2.st_mode;
1008 if (S_ISDIR(stb1.st_mode) && S_ISDIR(stb2.st_mode)) {
1009 printf("Common subdirectories: %s and %s\n", fullpath1, fullpath2);
1013 if (!S_ISREG(stb1.st_mode) && !S_ISDIR(stb1.st_mode))
1015 else if (!S_ISREG(stb2.st_mode) && !S_ISDIR(stb2.st_mode))
1018 val = diffreg(fullpath1, fullpath2, flags);
1020 print_status(val, fullpath1, fullpath2, NULL);
1024 #if ENABLE_FEATURE_DIFF_DIR
1025 static int dir_strcmp(const void *p1, const void *p2)
1027 return strcmp(*(char *const *) p1, *(char *const *) p2);
1030 /* This function adds a filename to dl, the directory listing. */
1032 static int add_to_dirlist(const char *filename,
1033 struct stat ATTRIBUTE_UNUSED * sb, void *userdata, int depth)
1036 dl = xrealloc(dl, dl_count * sizeof(char *));
1037 dl[dl_count - 1] = xstrdup(filename);
1038 if (cmd_flags & FLAG_r) {
1039 int *pp = (int *) userdata;
1040 int path_len = *pp + 1;
1042 dl[dl_count - 1] = &(dl[dl_count - 1])[path_len];
1047 /* This returns a sorted directory listing. */
1048 static char **get_dir(char *path)
1054 /* If -r has been set, then the recursive_action function will be
1055 * used. Unfortunately, this outputs the root directory along with
1056 * the recursed paths, so use void *userdata to specify the string
1057 * length of the root directory. It can then be removed in
1058 * add_to_dirlist. */
1060 int path_len = strlen(path);
1061 void *userdata = &path_len;
1063 /* Reset dl_count - there's no need to free dl as xrealloc does
1064 * the job nicely. */
1067 /* Now fill dl with a listing. */
1068 if (cmd_flags & FLAG_r)
1069 recursive_action(path, TRUE, TRUE, FALSE, add_to_dirlist, NULL,
1075 dp = warn_opendir(path);
1076 while ((ep = readdir(dp))) {
1077 if ((!strcmp(ep->d_name, "..")) || (!strcmp(ep->d_name, ".")))
1079 add_to_dirlist(ep->d_name, NULL, NULL, 0);
1084 /* Sort dl alphabetically. */
1085 qsort(dl, dl_count, sizeof(char *), dir_strcmp);
1087 /* Copy dl so that we can return it. */
1088 retval = xmalloc(dl_count * sizeof(char *));
1089 for (i = 0; i < dl_count; i++)
1090 retval[i] = xstrdup(dl[i]);
1095 static void diffdir(char *p1, char *p2)
1098 char **dirlist1, **dirlist2;
1100 int dirlist1_count, dirlist2_count;
1103 /* Check for trailing slashes. */
1105 if (p1[strlen(p1) - 1] == '/')
1106 p1[strlen(p1) - 1] = '\0';
1107 if (p2[strlen(p2) - 1] == '/')
1108 p2[strlen(p2) - 1] = '\0';
1110 /* Get directory listings for p1 and p2. */
1112 dirlist1 = get_dir(p1);
1113 dirlist1_count = dl_count;
1114 dirlist1[dirlist1_count] = NULL;
1115 dirlist2 = get_dir(p2);
1116 dirlist2_count = dl_count;
1117 dirlist2[dirlist2_count] = NULL;
1119 /* If -S was set, find the starting point. */
1121 while (*dirlist1 != NULL && strcmp(*dirlist1, start) < 0)
1123 while (*dirlist2 != NULL && strcmp(*dirlist2, start) < 0)
1125 if ((*dirlist1 == NULL) || (*dirlist2 == NULL))
1126 bb_error_msg(bb_msg_invalid_arg, "NULL", "-S");
1129 /* Now that both dirlist1 and dirlist2 contain sorted directory
1130 * listings, we can start to go through dirlist1. If both listings
1131 * contain the same file, then do a normal diff. Otherwise, behaviour
1132 * is determined by whether the -N flag is set. */
1133 while (*dirlist1 != NULL || *dirlist2 != NULL) {
1136 pos = dp1 == NULL ? 1 : dp2 == NULL ? -1 : strcmp(dp1, dp2);
1138 do_diff(p1, dp1, p2, dp2);
1141 } else if (pos < 0) {
1142 if (cmd_flags & FLAG_N)
1143 do_diff(p1, dp1, p2, NULL);
1145 print_only(p1, strlen(p1) + 1, dp1);
1148 if (cmd_flags & FLAG_N)
1149 do_diff(p1, NULL, p2, dp2);
1151 print_only(p2, strlen(p2) + 1, dp2);
1160 int diff_main(int argc, char **argv)
1165 llist_t *L_arg = NULL;
1167 opt_complementary = "L::";
1168 cmd_flags = getopt32(argc, argv, "abdiL:NqrsS:tTU:wu",
1169 &L_arg, &start, &U_opt);
1171 if (cmd_flags & FLAG_L) {
1173 if (label[0] == NULL)
1174 label[0] = L_arg->data;
1175 else if (label[1] == NULL)
1176 label[1] = L_arg->data;
1180 L_arg = L_arg->link;
1183 /* If both label[0] and label[1] were set, they need to be swapped. */
1184 if (label[0] && label[1]) {
1188 label[1] = label[0];
1193 context = 3; /* This is the default number of lines of context. */
1194 if (cmd_flags & FLAG_U) {
1195 context = xatoul_range(U_opt, 1, INT_MAX);
1201 * Do sanity checks, fill in stb1 and stb2 and call the appropriate
1202 * driver routine. Both drivers use the contents of stb1 and stb2.
1205 bb_error_msg("missing filename");
1208 if (strcmp(argv[0], "-") == 0) {
1209 fstat(STDIN_FILENO, &stb1);
1212 xstat(argv[0], &stb1);
1213 if (strcmp(argv[1], "-") == 0) {
1214 fstat(STDIN_FILENO, &stb2);
1217 xstat(argv[1], &stb2);
1218 if (gotstdin && (S_ISDIR(stb1.st_mode) || S_ISDIR(stb2.st_mode)))
1219 bb_error_msg_and_die("can't compare - to a directory");
1220 if (S_ISDIR(stb1.st_mode) && S_ISDIR(stb2.st_mode)) {
1221 #if ENABLE_FEATURE_DIFF_DIR
1222 diffdir(argv[0], argv[1]);
1224 bb_error_msg_and_die("directory comparison not supported");
1227 if (S_ISDIR(stb1.st_mode)) {
1228 argv[0] = concat_path_file(argv[0], argv[1]);
1229 xstat(argv[0], &stb1);
1231 if (S_ISDIR(stb2.st_mode)) {
1232 argv[1] = concat_path_file(argv[1], argv[0]);
1233 xstat(argv[1], &stb2);
1235 print_status(diffreg(argv[0], argv[1], 0), argv[0], argv[1], NULL);